The disclosure button to show the destination and listen menus is now a normal button instead of being a repurposed toolbar toggle button.

Pressed key highlights are drawn with a slight gradient.

New Global Hot Keys menu item.

New preferences to control the visibility of overlay notifications.

It is now possible to have no modifier key for global hot keys, so you only have to press the key corresponding to the note.

Key maps were extended to use more keys on the keyboard.

Non-English localisations have been disabled for this release due to the number of UI changes.

Added a preference to make the keyboard window transparent to mouse clicks when MidiKeys is in the background.

Made the keyboard window minimizable.

Reorganized the preferences window with several tabs.

Added preferences to control software updates.

MidiKeys is a small application for Mac OS X that presents a miniature MIDI keyboard onscreen. You can use the computer keyboard to play MIDI notes, or click on the keys with the mouse. There is also an option to select a MIDI source and see incoming notes played on the keyboard.

MidiKeys has no way to produce sound on its own. In order to hear a sound when you press keys, you need to connect the MidiKeys output to a synthesizer of some sort. This can be either a softsynth or a hardware synth connected through a MIDI I/O box. Apple's AU Lab works nicely to play Audio Units.